1. Field of the Invention
The present invention relates to a semiconductor including an oxide semiconductor. Note that here, semiconductor devices refer to general elements and devices which function utilizing semiconductor characteristics. For example, a memory, an arithmetic circuit, a rectifier, a display device, and the like which include a semiconductor can be given as semiconductor devices; however, the present invention is not limited thereto. For example, Patent Document 1 can be referred to for a memory including a semiconductor.
2. Description of the Related Art
In recent years, a transistor, a display device, a memory, and the like manufactured using a composite oxide of indium, gallium, and zinc have been reported (for example, see Patent Documents 2 to 5).